Add support for destructuring well-known and late-bound names

src/compiler/checker.ts

@@ -4174,14 +4174,17 @@ namespace ts {
                 else {
                     // Use explicitly specified property name ({ p: xxx } form), or otherwise the implied name ({ p } form)
                     const name = declaration.propertyName || <Identifier>declaration.name;
-                    if (isComputedNonLiteralName(name)) {
-                        // computed properties with non-literal names are treated as 'any'
+                    const isLate = isLateBindableName(name);
+                    const isWellKnown = isComputedPropertyName(name) && isWellKnownSymbolSyntactically(name.expression);
+                    if (!isLate && !isWellKnown && isComputedNonLiteralName(name)) {
                         return anyType;
                     }
 
                     // Use type of the specified property, or otherwise, for a numeric name, the type of the numeric index signature,
                     // or otherwise the type of the string index signature.
-                    const text = getTextOfPropertyName(name);
+                    const text = isLate ? getLateBoundNameFromType(checkComputedPropertyName(name as ComputedPropertyName) as LiteralType | UniqueESSymbolType) :
+                        isWellKnown ? getPropertyNameForKnownSymbolName(idText(((name as ComputedPropertyName).expression as PropertyAccessExpression).name)) :
+                        getTextOfPropertyName(name);
 
                     // Relax null check on ambient destructuring parameters, since the parameters have no implementation and are just documentation
                     if (strictNullChecks && declaration.flags & NodeFlags.Ambient && isParameterDeclaration(declaration)) {

tests/baselines/reference/destructuredLateBoundNameHasCorrectTypes.errors.txt

@@ -0,0 +1,18 @@
+tests/cases/compiler/destructuredLateBoundNameHasCorrectTypes.ts(11,7): error TS2459: Type '{ prop: string; }' has no property '[notPresent]' and no string index signature.
+
+
+==== tests/cases/compiler/destructuredLateBoundNameHasCorrectTypes.ts (1 errors) ====
+    let { [Symbol.iterator]: destructured } = [];
+    void destructured;
+
+    const named = "prop";
+
+    let { [named]: computed } = { prop: "b" };
+    void computed;
+
+    const notPresent = "prop2";
+
+    let { [notPresent]: computed2 } = { prop: "b" };
+          ~~~~~~~~~~~~
+!!! error TS2459: Type '{ prop: string; }' has no property '[notPresent]' and no string index signature.
+

tests/baselines/reference/destructuredLateBoundNameHasCorrectTypes.js

@@ -0,0 +1,22 @@
+//// [destructuredLateBoundNameHasCorrectTypes.ts]
+let { [Symbol.iterator]: destructured } = [];
+void destructured;
+
+const named = "prop";
+
+let { [named]: computed } = { prop: "b" };
+void computed;
+
+const notPresent = "prop2";
+
+let { [notPresent]: computed2 } = { prop: "b" };
+
+
+//// [destructuredLateBoundNameHasCorrectTypes.js]
+let { [Symbol.iterator]: destructured } = [];
+void destructured;
+const named = "prop";
+let { [named]: computed } = { prop: "b" };
+void computed;
+const notPresent = "prop2";
+let { [notPresent]: computed2 } = { prop: "b" };

tests/baselines/reference/destructuredLateBoundNameHasCorrectTypes.symbols

@@ -0,0 +1,29 @@
+=== tests/cases/compiler/destructuredLateBoundNameHasCorrectTypes.ts ===
+let { [Symbol.iterator]: destructured } = [];
+>Symbol.iterator : Symbol(SymbolConstructor.iterator, Decl(lib.es2015.iterable.d.ts, --, --))
+>Symbol : Symbol(Symbol, Decl(lib.es2015.symbol.wellknown.d.ts, --, --), Decl(lib.es2015.symbol.d.ts, --, --), Decl(lib.es2015.symbol.d.ts, --, --))
+>iterator : Symbol(SymbolConstructor.iterator, Decl(lib.es2015.iterable.d.ts, --, --))
+>destructured : Symbol(destructured, Decl(destructuredLateBoundNameHasCorrectTypes.ts, 0, 5))
+
+void destructured;
+>destructured : Symbol(destructured, Decl(destructuredLateBoundNameHasCorrectTypes.ts, 0, 5))
+
+const named = "prop";
+>named : Symbol(named, Decl(destructuredLateBoundNameHasCorrectTypes.ts, 3, 5))
+
+let { [named]: computed } = { prop: "b" };
+>named : Symbol(named, Decl(destructuredLateBoundNameHasCorrectTypes.ts, 3, 5))
+>computed : Symbol(computed, Decl(destructuredLateBoundNameHasCorrectTypes.ts, 5, 5))
+>prop : Symbol(prop, Decl(destructuredLateBoundNameHasCorrectTypes.ts, 5, 29))
+
+void computed;
+>computed : Symbol(computed, Decl(destructuredLateBoundNameHasCorrectTypes.ts, 5, 5))
+
+const notPresent = "prop2";
+>notPresent : Symbol(notPresent, Decl(destructuredLateBoundNameHasCorrectTypes.ts, 8, 5))
+
+let { [notPresent]: computed2 } = { prop: "b" };
+>notPresent : Symbol(notPresent, Decl(destructuredLateBoundNameHasCorrectTypes.ts, 8, 5))
+>computed2 : Symbol(computed2, Decl(destructuredLateBoundNameHasCorrectTypes.ts, 10, 5))
+>prop : Symbol(prop, Decl(destructuredLateBoundNameHasCorrectTypes.ts, 10, 35))
+

tests/baselines/reference/destructuredLateBoundNameHasCorrectTypes.types

@@ -0,0 +1,38 @@
+=== tests/cases/compiler/destructuredLateBoundNameHasCorrectTypes.ts ===
+let { [Symbol.iterator]: destructured } = [];
+>Symbol.iterator : symbol
+>Symbol : SymbolConstructor
+>iterator : symbol
+>destructured : () => IterableIterator<undefined>
+>[] : undefined[]
+
+void destructured;
+>void destructured : undefined
+>destructured : () => IterableIterator<undefined>
+
+const named = "prop";
+>named : "prop"
+>"prop" : "prop"
+
+let { [named]: computed } = { prop: "b" };
+>named : "prop"
+>computed : string
+>{ prop: "b" } : { prop: string; }
+>prop : string
+>"b" : "b"
+
+void computed;
+>void computed : undefined
+>computed : string
+
+const notPresent = "prop2";
+>notPresent : "prop2"
+>"prop2" : "prop2"
+
+let { [notPresent]: computed2 } = { prop: "b" };
+>notPresent : "prop2"
+>computed2 : any
+>{ prop: "b" } : { prop: string; }
+>prop : string
+>"b" : "b"
+

tests/cases/compiler/destructuredLateBoundNameHasCorrectTypes.ts

@@ -0,0 +1,12 @@
+// @target: es6
+let { [Symbol.iterator]: destructured } = [];
+void destructured;
+
+const named = "prop";
+
+let { [named]: computed } = { prop: "b" };
+void computed;
+
+const notPresent = "prop2";
+
+let { [notPresent]: computed2 } = { prop: "b" };